Solar generation and cogeneration systems are becoming a logical alternative or addition to fossil fueled energy systems as fuel costs and environmental concerns increase. The solar heat that is simultaneously collected with electricity provides a major boost to an energy system's value. Unfortunately, however “solar cogeneration” systems need to be located at the site of use, which presents challenges to most existing or previous photovoltaic concentrator methods. Since the collected heat generally is at low temperature (typically 40-80 degrees C.), the heat energy cannot be transmitted far without substantial parasitic losses. Further, the capital cost of hot water and other heat transmission systems favors direct on site use. And, such low temperature heat generally cannot be converted in a heat engine to mechanical or electrical power because of the small temperature differential versus ambient temperatures. Accordingly, systems are needed that harvest light energy and transfer the harvested energy easily to the heating, lighting and electricity requirements at the site of use, such that the immediate needs of the site are factored into how the system is controlled.
Solar cogeneration technologies are, in part, held back by challenges in creating optical systems that are both inexpensive and that can be mounted or integrated into a building. One problem is the practical limit for how tall a design can be to withstand forces from windy conditions on the device and building on which it may be mounted. Tying a cogeneration apparatus into the foundation or load bearing structure of a building creates expensive installations and/or mounting systems to accommodate system stresses, particularly on the roof. Many commercial sites lack sufficient ground space for a reasonably sized system and roof-mounting is the only viable option to obtain sufficient collector area.